Shedding mechanism for looms



M8,) 26, 1936. c. D. BROWN 2,042,422

SHEDDING MECHANISM FOR LOOMS Filed Dec. 21, 1955 INVENTOR.

CARL D. EEOWN.

' ATTORNEY.

Patented May 26, 1936 UNITED STATES PATENT OFFICE Carl D. Brown,Hopedale, Mass,

assignor to I Draper Corporation, Hopedale, Mass, at corporation ofMaine Application December 21, 1935, Serial No. 55,638

10 Claims.

The present invention pertains to the shedding mechanism of looms andmore particularly relates to the cam type of such mechanism.

Looms of the type to which my invention pertains have a plurality ofharness frames connected with and operated by reciprocating harnesstreadles, the treadles being reciprocated about a fixed axis by suitablecams. The throw of the cams and the length of the treadles are properlyproportioned to produce a movement of the harness frames which willprovide the desired opening of the warp for the passage of a shuttle.The warp opening is generally kept as small as possible, consistent withproper passage of the shuttle, but must be varied in accordance with thesize of the shuttle, and with other weaving conditions. For this reason,a tremendous number of sizes of harness cams is required, both forequipping new looms and for replacement purposes in adapting existinglooms to different weaving conditions. It has been proposed heretoforeto eliminate most of the cam sizes required, by making the sheddingmechanism adjustable in one manner or another, to thereby provide foradjustment of the warp opening obtainable from a given harness cam. Inthis connection, reference is made particularly to patent to A. E.Rhoades, No. 1,312,751, granted Aug. 12, 1919, wherein it was proposedto provide adjusting means for the fulcrum of the harness treadles. The.Rhoades construction did not prove satisfactory, and accordingly wasnot used commercially, principally because the adjustable parts wereinaccessible and inconvenient to adjust.

The principal object of the present invention is ,to provide, in ashedding mechanism, a harness frame, harness treadle for operating theframe, harness cam for operating the treadle, andad justable fulcrumdevices for the treadle, which fulcrum devices shall comprise a gear andrack which shall be accessible and easy toadjust.

In the preferred embodiment of the invention, conventional harnessframes are reciprocated by harness treadles positioned below the harnessframes and extending rearwardly from the planes thereof. Harness camsengage the treadles for depressing the same in the usual manner. Therearward ends of the treadles are provided with rack teeth, the treadlesresting on an elongated igear member which extends transversely of thetreadles and constitutes the fulcrum therefor. "The gear member isadjustable longitudinally of the treadles, or of the racks thereon, forvarying the fulcrum point, and thereby adjusting the warp opening.

The said preferred embodiment is illustrated on the accompanyingdrawing, of which:

Fig. 1 is a view partly in section and partly in elevation, showing theshedding mechanism of a loom to which my invention has been applied; and

Fig. 2 is a horizontal sectional view taken approximately on line 2--2,Fig. 1. '10

The loom shown on the drawing is, except for the shedding mechanism, ofconventional construction, and accordingly is but fragmentarilyillustrated. Of the conventional construction there is shown the righthand loom side I, which is connected to a left hand loom side (notshown) by a plurality of cross members, as girt 2. The front of the loomis at the right of Fig. 1 of the drawing. The loom also has crank shaft3, a cam shaft 4, and an auxiliary shaft 5 for carrying a plurality'ofharness cams 6, to be further mentioned.

The specificembodiment of the invention here- 'in disclosed includes avery common arrangement of harness frames 1, wherein a plurality of suchframes extend widthwise of the loom' in adjacent vertical, orsubstantially vertical, planes and are adapted to be reciprocatedvertically by the cams 6 and harness treadles 8 positioned below theharness frames. The shedding mechanism shown is further conventional inthat the harness treadles, to the desired plural number, are positionedparallel to each other, side by side, and extending rearwardly from theplanes of the harness frames. The forward end of each treadle 5 isconnected to a harness frame by any usual means, such as strap 9.

The rotating harness cams 6 are positioned above the treadles,intermediate the ends of'the latter, each harness cam serving to depressits respective treadle through engagement with the roller l0 thereon.The harness treadles being fulcrumed at their rearward ends in thisparticular form of shedding mechanism, depression of a treadle resultsin the connected harness frame being depressed an amount whichcorresponds to the throw of the forward end of the treadle. No means forraising the harness frames is herein disclosed, any of a number of wellknown top motions, so -called, being adapted to such purpose. Referencemay be had, for example, to the top motion disclosed in patent to Bell,No. 1,580,948, granted April 13, 1926,

In accordance with the invention, the fulcrum for the treadle iscomprised of a gear member ll ..55

the same along position, the same comprising a plate 2| .to fit over theend of a stud portion 11 or .supporting brackets.

which has teeth l2 extending transversely of the treadle and meshingwith rack teeth l3 formed. on the latter. In the specific embodimentshown,

the gear member H is elongated sufliciently to' engage and support therearward ends of all of the harness treadles 8, there being .but twosuch treadles, in recip treadles shown. The harness rocating, rock onthe gear member, which is normally fixed. It will be apparent thatshifting the gear member longitudinally of the treadles, that is,forwardly or rearwardly, without shifting the treadles, will serve tosimulanteously and equally vary the throw of the treadles, therebyvarying the size of warp opening obtainable from the one set of harnesscams. r

The gear member Il may be supported for the above mentioned adjustmentby being adjustably mounted in brackets, as 14 and I5, which are boltedto the girt 2. The brackets are provided with slots l6 which extendgenerally longitudinally of the treadles. The gear member is provided atits ends with integral stud portions l1 and I8 which are positioned inthe slots IS. The gear member H may be, as shown, cast in segmentalform, with an attendant saving in weight and cost, the segmental gearusually providing ample adjustment.

I prefer toadjust'the gear member by rolling the racks l3. This rollingmovement is facilitated by a fixed rack which engages the teeth of thegear member and prevents the latter from moving longitudinally of thetreadles without also rotating. Two such racks are shown at H) and 20,there being one rack formed integrally with each of the supportingbrackets l4 and IS. The teeth of these fixed racks mesh with the teethl2 of the gear member at the ends of the latter.

There is shown on the drawing a convenient means for fixing the gearmember I l in adjusted at each Each plate is apertured l8 and is alsoslotted to receive a bolt, as 22, by which it may be fastened to therespective bracket 14 or I5. When the plates are thus fastened, theysecurely hold the gear member in adjusted position. However, when thefastening bolts are loosened, the plates, which are accessible from therear of the loom, may be pushed forwardly or pulled rearwardly tothereby roll the gear member alongthe racks on the treadles, as abovedescribed.

The treadles 8 as shown are each provided with a slot 23 on one side anda projecting lug 24 on the other side, to facilitate meshing of theproper teeth of the treadle racks with the teeth of the gear member wheninstalling the treadles on the loom. The treadles are also provided withguide grooves, as 25, to receive guide rods such as rods 26, 26, whichmay be adjustably mounted in the The guide rods serve to prevent thetreadles from spreading apart or separating during the normal operationof the loom. The rods may be adjusted to accommodate more than the, twotreadles shown.

The embodimentof the invention above described is extremely simple, bothin its construction and in the'manner of its use. The single end of thegear member.

'elongated'gear member is further desirable in that it provides equaladjustment for all treadles, and will, within limits, provide a fulcrumof the "for any desired number of treadles. The invennan accordinglyprovides a practicalform of said treadle, said means shedding mechanismwherein the warp opening obtainable may be varied or adjusted withoutthe necessity of changing the harness cams.

Having fully disclosed the preferred embodiment of my invention, Iclaim:

1. In a loom, a harness frame, a harness treadle connected with saidharness frame for operating the latter, a cam for operating saidtreadle, and

means constituting an adjustable fulcrum for member having teethextending transversely of the treadle and meshing with rack teeth formedon the latter, means supporting said gear member for adjustmentlongitudinally of the treadle along said rack, and means for fixing saidgear in adjusted position.

2. In a loom, a harness frame, a harness treadle connected with saidharness frame for operating the latter, a cam for operating saidtreadle, a gear member on which said treadle is fulcrumed, said gearmember having gear teeth extending transversely of the treadle andmeshing with rack teeth formed on the latter, means supporting said gearmember for rolling movement longitudinally of the treadle along saidrack to thereby adjust the fulcrum point of the treadle, and means forfixing said gear member in adjusted position.

consisting .of a gear 3. In a loom, a harness frame, a harness treadleversely of the treadle and meshing with rack teeth formed on the latter,brackets having slots in which said gear member is supported formovement in a direction longitudinally of said treadle, a fixed rackengaging the teeth of. said gear member for causing the latter to rollon the first said rack as the gear member is moved along said slots, andmeans for fixing said gear member in said slots.

4. In a loom, a plurality of harness frames, a plurality of parallelharness treadles each connected with a harness frame for operating thesame, cams for operating said treadles, a single elongated gear memberon which all of said treadles are fulcrumed, said gear member havinggear teeth extending transversely of said treadles and meshing with rackteeth formed on the latter, means supporting said gear member forrolling movement longitudinally of said treadles along the racksthereon, to thereby simultaneously and equally adjust the fulcrum pointsfor all of the treadles, and means for fixing said gear member inadjusted position.

5. In a loom, a harness frame, a harness treadle connected at one endthereof with said harness frame for operating the latter, a harness.

cam engaging said treadle intermediate the ends of the latter, a gearmember having teeth meshing with rack teeth formed in the other end ofsaid treadle, said gear member constituting the fulcrum for saidtreadle, means supporting said extending .widthwise of the loqm, aharness treadle positioned beneath said harness frame and extending atright angles to the plane thereof,

frame positioned in a substantially vertical plane means connecting theforward end of said tre'adle with said harness frame, a harness camengaging said treadle intermediate the ends of the latter forreciprocating said treadle and harness frame, a gear member having gearteeth meshing with rack teeth formed on the rearward end of the treadle,said gear member constituting the fulcrum for said treadle, meanssupporting said gear member for adjustment forwardly and rearwardly byrolling the same along said rack, and means for fixing said member inadjusted position.

7. In a loom, a plurality of harness frames, a plurality of harnesstreadles each connected at one of its ends with a harness frame, saidtreadles being positioned side-by-side in parallel planes, a harness camfor each of said treadles, each harness cam engaging its respectivetreadle intermediate the ends of the latter, a single elongated gearmember having gear teeth which extend transversely of said treadles,each said treadle having rack teeth meshing with the first said teethwhereby said member constitutes a fulcrum for all of said treadles, andmeans for simultaneously varying the throw of all of said treadles byrolling said gear along said racks without moving said treadles relativeto said cams and harnesses. I

8. In a loom, a harness frame, a harness treadle connected at one endthereof with said harness frame for operating the latter, a harness camengaging said treadle intermediate the ends of the latter, a gear memberhaving teeth meshing with rack teeth formed in the other end of saidtreadle, said gear member constituting the fulcrum for said treadle, afixed rack engaging the teeth of said gear member and normallypreventing the latter from rotating, means supporting said member forrolling movement along said racks, to thereby adjust the fulcrum of thetreadle longitudinally of the latter, and means for fixing said memberin adjusted position.

9. In a loom, a vertically movable harness frame, a harness treadlepositioned below said harness frame and extending rearwardly from theplane thereof, means connecting the forward end of said treadle withsaid harness frame substantially in the said plane, a cam positionedabove said treadle intermediate the ends thereof and adapted to depressthe treadle to thereby lower said harness frame, a fulcrum for saidtreadle consisting of a gear member positioned beneath the rearward endof the treadle, said gear member having teeth extending transversely ofthe treadle and meshing with rack teeth formed in the lower facethereof, means supporting said gear member for rolling movement alongsaid rack teeth to thereby adjust the gear member longitudinally of thetreadle, and means for fixing said gear member in adjusted position.

10. In a loom, a plurality of vertically movable harness framespositioned in adjacent planes and extending widthwise of the loom, aplurality of harness treadles positioned side by side below said harnessframes and extendin'g rearwardly from said planes, the forward end ofeach of said treadles being connected with a harness frame, camspositioned above said treadles intermediate the ends thereof, each cambeing adapted to depress a. treadle to thereby lower a harness frame, asingle fulcrum member for all of said treadles, said member consistingof an elongated gear member extending transversely of said treadlesbeneath the rearward ends thereof, said member having. gear teethmeshing with rack teeth formed on said treadles, means supporting saidgear member for adjustment longitudinally of the treadles, and means forfixing said member in adjusted position.

CARL D. BROWN.

